Reusable space launch vehicles may require thermal insulation to protect the vehicle from heat during reentry. Currently, flexible ceramic thermal protection blankets may be used to cover a portion of the exterior of such vehicles for heat protection. In some applications, the thermal protection blanket may be attached to a frame on the vehicle at multiple frame attachment points. Because the blanket may not be directly locked to the frame but may be sewn around it, however, the blanket may shift slightly relative to the frame during vehicle operation. The in-plane motion of the blanket may lead to excessive rubbing and wear of the sidewalls of the blanket against adjacent structure.
One approach to reducing excessive wear of the thermal protection blanket may include the use of batting to fill any pockets around the frame to “pot” the frame tightly within the blanket. Additionally, the sewing thread for the construction of the blanket itself may be stitched as close to the frame as possible such that the thread may form tight channels into which the frame can be locked. One drawback of this method is that the batting may be too soft and crushable to withstand pressures from movement of the blanket relative to the frame. Moreover, sewing processes may prevent the stitch lines from being sewn close enough to the frame to effectively lock it in place.
Another approach to reducing excessive wear of the blanket may include sewing of the frame directly to the IML layer of fabric on an outer blanket and then filling of the gap between the primary structure and the frame with a second OML blanket that is bonded to the structure. However, this approach may require bonding of the second IML blanket to the structure and may add weight to the vehicle.
Therefore, a blanket assembly having a thermal protection blanket which is mechanically attached to a fabric-covered attachment frame to minimize in-plane shear movement of the thermal protection blanket due to vibration, acoustic, aerodynamic or structural deflection loads is needed to enhance longevity of the blanket.